It is well known in the art to affix trim strips to the sides of motor vehicles to protect the paint work of the vehicle from damage caused by impact of opening car doors in parking lots and the like. The trim strips protrude from the sides of the motor vehicles to intercept the impacting object. The simplest trim strips are merely strips of aluminum or the like which are screwed or similarly fastened to the motor vehicle sides. These trim strips suffer from the drawback of non-resilience in that although they protect the paint work of the motor vehicle they themselves become battered and disfigured from impact.
An improved trim strip comprises an extruded aluminum channel with an outwardly concave shape and a rubber bumper insert configured to be fittingly retained by the channel. The bumper insert protrudes from the channel so as to receive impact and resists disfiguration due to its resilience. In order to prevent axial disengagement of the bumper insert from the channel, end caps are firmly secured to the opposite ends of the channel. Typical trim strips of this general type are disclosed in U.S. Pat. Nos. 3,606,432 and 3,752,521.
However, various problems have remained heretofore unsolved in the construction of the trim strips such as those disclosed in the above patents. Owing to the extremely thin metal presently being used in the construction of bodies and doors of passenger automobiles and the correspondingly low resistance to buckling, even if a prior art trim strip is provided on a vehicle door a relatively small impact to the trim strip transmitted to the vehicle door may under some circumstances be sufficient to buckle the adjacent door or body material, crack the paint and possibly leave a permanent dent.
Although a solution to the problem is to make the trim strip wider in order to distribute the impact force over a larger area, the prior art construction makes the embodiment of this concept relatively expensive due to the increased mass of the larger resilient bumper insert.
Another drawback of the particular trim strips disclosed in the above patents is the relatively complex configuration of the end caps which are designed for rigid attachment to the channel, such end caps being expensive to manufacture.